[GTK] Report isMinimized and correctly restore app windows.

chrome/browser/ui/gtk/extensions/native_app_window_gtk.h

Index: chrome/browser/ui/gtk/extensions/native_app_window_gtk.h
diff --git a/chrome/browser/ui/gtk/extensions/native_app_window_gtk.h b/chrome/browser/ui/gtk/extensions/native_app_window_gtk.h
index 2b71243778cd78b8d359be9e9813538f2a6f9ad3..ce5ece9b0ed1ec5c7cb029350c9ad565e61ad285 100644
--- a/chrome/browser/ui/gtk/extensions/native_app_window_gtk.h
+++ b/chrome/browser/ui/gtk/extensions/native_app_window_gtk.h
@@ -15,6 +15,7 @@
 #include "third_party/skia/include/core/SkRegion.h"
 #include "ui/base/gtk/gtk_signal.h"
 #include "ui/base/x/active_window_watcher_x_observer.h"
+#include "ui/base/x/x11_atom_cache.h"
 #include "ui/gfx/rect.h"
 
 class ExtensionKeybindingRegistryGtk;
@@ -102,6 +103,9 @@ class NativeAppWindowGtk : public NativeAppWindow,
                        GdkEventMotion*);
   CHROMEGTK_CALLBACK_1(NativeAppWindowGtk, gboolean, OnButtonPress,
                        GdkEventButton*);
+  // Callback for PropertyChange XEvents.
+  CHROMEG_CALLBACK_1(NativeAppWindowGtk, GdkFilterReturn,
+                     OnXEvent, GdkXEvent*, GdkEvent*);
 
   void OnConfigureDebounced();
 
@@ -155,6 +159,11 @@ class NativeAppWindowGtk : public NativeAppWindow,
   // updating its dimensions.
   ObserverList<web_modal::WebContentsModalDialogHostObserver> observer_list_;
 
+  ui::X11AtomCache atom_cache_;
+
+  // True if we listen for the XEvent.
+  bool is_x_event_listened_;
+
   DISALLOW_COPY_AND_ASSIGN(NativeAppWindowGtk);
 };